Gyroscopic compass



oct 9, 192s. 1,686,524

W. R. HIGHT GYROSCOPIC COMPASS 7 f will@ /2 INVENToR Wl'aBnK/V' /1Patented Qct. 9, 19218.

UNITED STATES 1,686,524 PATENT OFFICE.

-WILLIAM R. Hl'GrHT, OF HOLLIS, NEW YORK, .SSIGNOR T0 THE SPERRYGYROSCOPE COMPANY, or NEW YORK, N. Y.,

A CORPORATION OF NEW YORK.

.GYOSCOPIC COMPASS.

Application med November 7, '1925. serial No. 67,625.

This invention relates to gyroscopie compasscs in which means areemployed to eliminate the error or loscillation Otherwise set up whent-he ship on which the compass is mounted accelerates or turns.V It hasbeen 'found that oscillations are set up at this time by the dampingfactor of the compass vand to overcome this it has been proposed toeliminate or greatly reduce the damping duringr this time. I have found,however, that the elimination of the damping, while it lessens suchoscillations, does not entirely eliminate them unless further'and othermeans Iare employed in connection therewith,

It has long been' known that the period of a gyroscopic compass has avital relation to the proper behavior thereof on turning or accelerationof the ship, and it' has been found that a period of about 85 minutes isthe most satisfactory. I have found, however, that even though a compassbe designed for this period that when the damping is eliminated,oscillations are still present, and I have determined that one cause ofsuehoscillations is the fact that the elimination of the damping resultsin a shortening of the period of the compass by some 1() to 12 minutes,depending on the damping factor employed. The result is that when theship turns or accelerates the compass does not reach the new settlingpoints at the same time that the acceleration ceases, resulting in thesetting up of an oscillation.

. It is one of the objects of this invention to avoid the aforementioneddiiiculty and to devise a compass which will be unaffected byacceleration or turning of the ship by reason of the elimination of thedamping at that time by imparting to the compass the proper period atthat time.

Referring to the drawings in which what I now consider the preferredforms of my invention are shown Fig. 1 is a south elevation of thecompass, part-1y in section, embodying my invention.

Fig. 2 is a detail, partly 1n section, of. a modified, form of theinvention.

To illustrate my invention, I have shown it applied to the Sperry typecompass employing a liquid control system and have shown the damping asbeing-eliminated 'by the method disclosed in the co-pendinor applicationof Herbert I-I. Thompson, Serial No. 436 900, filed January 13, 1921. Itwill be obvious, however, that my invention may be applied to otherformsof Compasses and other types of damping eliminators withoutdeparting from the spirit of the invention as defined in the appendedclaims.

The casing of the gyroscope proper isshown at- 1, the same being mountedfor os,- cillation about a horizontal axis 2 3 in the vertical ring 4:..Said ring in turn is journaled for turning about a vertical axis by topbearing 6 and the bottom bearing (not shown) in the follow-up ring 7,which in turn is journaled for rotation Within the spider 8. Thefollow-up ring is driven in the usual manner by the follow-up motor 9.Pivoted on the follow-up ring is the usual liquid control gravitationalsystem or factor 10 by which the north seeking property is imparted tothe compass. Said system is shown as connected to the bottom of the caseby an arm 11. normally connected to the case at a point slightlyeccentric to the vertical line through the center thereof, by which thedamping factor is introduced in a manner well understood in the art.Said arm is pivoted on the box 12 at 13 so that the eccentricity of theconnection may be varied or eliminated at will. An electro-magnet 14 isshown' for substantially eliminating or greatly reducing theeccentricity of the connection and thereby the damping, so that whensaid electro-magnet is excited the arm 11 is rotated counterclockwisethrough a. small angle, thereby moving it to a position Where theconnection of the same with the damped, is longer than the normal minuteperiod so that when the damping is eliminated its period will be equalto the 85 minutes required, or, second. I may design the compass so asto have atl all times the proper period by varying said period at thesame time that the damping is eliminated.

One form that the. mechanism may assume for effecting this purpoe is asfollows; Each whereby the .amount of liquid flowing beat 13 and themovement thereof is effected v by means of a link 40 connected to lever41.I plvoted at 42 and pinnedl at its upper end to around a collar 44 onthe valve.

tween the boxes is varied b cutting off a portion of the. liquid to onesidle of the partition. To effect this I have shown a slidable valve 17having cut-away sections 18 and 19 normally in communicationrespectively nwith the port 2O leading to the part 21 to the left of thepartition 16, and with port 22 leading to the portion 23 of the box tothe right of the partition.

A channel 24 is provided in the casing 25 for the valve so that in thiscondition the mercury in both boxes is free to flow through l the pipe26 connecting the containers. When, however, the valve is moved to theleft in Fig. 1, port 20 is closed by the enlarged portion 27 of saidvalve, thereby cutting off the mercury in compartment 21. The movementof the valve is shown as effected by a lever 28 pivoted at 29 on the box12 and connected at. its upper end to the armature 30 of the solenoid31. The solenoid is normally maintained in the position shown in thefigure by means of spring 32 located on an extension or stem 33 of thevalve and between the box 12 and the collar 34 on said stem. When,however, the solenoid is excited, the armature is drawn inwardly therebymoving the valve to the left as explained. Preferably the solenoid isplaced in the same electrical circuit with the magnet 14 so that themovement of the valve occurs simultaneously with the elimination of thedamping. The movement of the valve results in lessening the effectivearea of the mercury operating on the compass by cutting off a portionthereof, thereby resulting in a lengthening Vofthe period at this timeby the reduction of the gravitational factor. Itwill be understood thatvalve 17, together with the actuating mechanism therefor, is duplicatedon the other side of the compass.

An alternative system for effecting the above is shown in Fig. 2 inwhich both functions are accomplished by a single solenoid; In thisligure the eccentric arm 11 is shown as pivoted to thelbottom of thecontainer 12 the core 30 of the solenoid 3l. Said lever 41 1s also cnnected to th'e valvej17 by means of acforke -armv 43, the fork thereoftaking in this inst-ance Works oppositely to the valve above describedin that lit shuts off one `compartment when moved to the right insteadof to the left, and in this instance also the solenoid 31 is normallyexcited, that is, when damping is present, and is deenergized when p Itwould be understood, therefore, that the switch 15 is Thervalvemanipulated oppositely t-ovswitch 15. In other words, switch 15 isclosed when switch 15 isopened and vice versa. When the solenoid isenergized, therefore, the core 30 is drawn to the right therebymaintaining the valve 17 to the left against the act-ion of the spring32 and also'maintaining the arm 11 to the left in its damping position.At this time the cut-away portion 45 of said valve extends across both.ports 20 and 22 so that all the mercury vis free to Aflow througl'i pipe26. When,u however, the solenoid 31. is deenergized, the core moves tothe left bythe action of the spring and the valve moves to the rightclosing the port 20 and'nioving at the same time the arm 11counterclockwise to eliminate the damping.

In accordance with the provisions of the patent statutes, I have hereindescribed the principle and operation of my invention, together with theapparatus which I nowy consider to represent the best embodimentthereof, but I desire to have it'understood that the apparatus shownisonly illustrative and that `the invention can be carried out by othermeans. Also, while it is designed to use the various" features andelements in the combination and relations described, some of these maybe altered and others omitted without interfering with the morevgeneralresults outlined, and the invention extends to such use.

Having described my invention, what I claim and desire to secure byLetters Patent is:

1. In a gyro-compass having adamping factor, of'means for substantiallyeliminating the damping, and means for giving the compasssubstantiallyan `minute period while the damping is eliminated;

2. In a gyro-compass-.having a damping factor, of means for reducingthedamping, thereby tending to vshorten'they period of the compass, andmeans for preventing the period of the compass'from shortening whileDthe damping is reduced. i

3. Ina gyro-compass, means for varying thev period thereof by alteringlthe effective gravitational factor,and means for operating saidirst-namedmeans to .lengthen the period when the ship/turns oraccelerates.

4. `In a gyro-comp'as's" having a damping factor and al gravitationallfactor,'of means fo'r reducing the damping'factor, and .means broughtinto action'by said first -named means for also lessening thegravitationalv factor.

5. In a gyro-compass hav-ing a damping' i cating meas,electro-mechanical means for varying the number of containers on eachside of the compass which are in communication with the containers onthe other side thereof and means whereby said first-named means may beactuated when the ship turns.

7. In a gym-compass, a liquid control gravitational factor therefor,comprising a liquid container on each side of the gyrossope andconnectedl by communicating means, electromechanical means area of eachcontainer which is in communication with` the other container, and meanswhereby said electro-mechanical means may be actuated when the shipturns.

for varying the elective 8. In a gym-compass, a liquid controlgravitational factor therefor, comprising a liquid container on eachside of the gyroscope and connected'by communicating means, a normallyeccentric connection between said containers and the gyroscope,electro-mechanical means for varying the effective area of eachcontainer which is in communication with the other contalner and forsimultaneously connection, 2,5

varying the eccentricity of said and means whereby saidelectro-mechanical means may beactuated when the ship turns.

In testimony whereor` I have aflixed my signature.

' WILLIAM It. HIGHT.

